For those who doubt:
This happened overnight in a system that was always left pressurized. Pieces were embedded in the wall and ceiling, and the main chunk that blew off was under a bench on the other side of the shop. It kicked so hard that it broke an elbow on the other end of the run as well. The compressor burned up due to running all night.
OSHA also forbids the use of PVC in air systems. I have worked in shops with both galvanized and copper, both new and with 15-30years of use, and either works great. Galvanized pipe will corrode over time, but it then leaks, it doesn't blow up.
As far as size, 3/4 is good. 1/2 works, but the larger size allows less resistance, plus adds air storage capacity.